Dwayne Johnson battled depression for years after witnessing his mom's attempted suicide.

When he was 15, she walked into traffic but has no memory of the incident now.

In the years to follow Johnson went through several difficulties and at one point was "crying constantly."

Dwayne "The Rock" Johnson battled depression for years after witnessing his mom's attempted suicide.

In an interview with the UK newspaper Daily Express, Johnson, a wrestler turned actor, said that when he was 15 his mom tried to end her own life by walking into traffic.

"She got out of the car on Interstate 65 in Nashville and walked into oncoming traffic," Johnson told the Express. "I grabbed her and pulled her back on the gravel shoulder of the road." Johnson said his mom now has no memory of the incident, but it's "probably best she doesn't."

Johnson contended with depression for years after the incident as a series of disappointing events followed. His dream of playing professional football ended with multiple injuries, and his girlfriend at the time broke up with him.

"I reached a point where I didn't want to do a thing or go anywhere," Johnson said. "I was crying constantly."

Johnson found the strength to get through it, he said.

"We both healed but we've always got to do our best to pay attention when other people are in pain," Johnson said. "We have to help them through it and remind them they are not alone."

On Sunday night, Johnson tweeted about the article: "Got tons of responses to this. Thank you. We all go [through] the sludge/s--- and depression never discriminates. Took me a long time to realize it but the key is to not be afraid to open up. Especially us dudes have a tendency to keep it in. You're not alone."